Device-to-Device (“D2D”) communication allows wireless mobile stations to communicate directly with one another with minimal use of network resources. To set up a typical D2D communication session in a Long-Term Evolution (“LTE”) network, the enhanced Node B (“eNB”) identifies a pair of mobile stations, allocates radio network resources (e.g., a portion of the cellular spectrum, which can be expressed in terms of sets of resource blocks (“RBs”) in specific subframes) to the devices, and broadcasts information about the allocated radio network resources. Using the allocated resources, the mobile stations can transmit and receive data between themselves without the need for the eNB to relay the data.
Current D2D communication schemes require resource allocation to be performed independently for each device in a pair or a group. This approach can result in inefficiencies because it requires the eNB to send a separate control message to each individual mobile station to let it know which RBs to use for D2D communication. Sending separate control messages increases signaling overhead for the eNB.
One way to address this problem is to allocate D2D resources well in advance and on a long-term basis. Doing so, however, significantly reduces the amount of control the eNB (and hence the network operator) can exercise over the mobile stations. For example, once mobile stations are able to synchronize with one another, they can use the allocated D2D resources and disregard any limitations imposed by the eNB.